Modeling of grain refinement: Part I. Effect of the solute titanium for aluminum

Abstract

Over the past few decades, the grain refinement of Al alloys has been extensively investigated theoretically and experimentally. However, the relative importance of the parameters that contributes to grain refinement still remains unclear and is likely to be dependent on specific solidification conditions. This paper aims to investigate the mechanisms by which Ti, a common grain-refining addition in commercial-purity aluminum (CP), contributes to grain refinement using a cellular automaton-finite control volume method (CAFVM). CAFVM is used to model the grain formation and microstructure morphology under different conditions, e.g., with and without refiners, for Al alloys. In this Part I, the effect of adding solute of Ti on grain formation through its effect on growth restriction, constitutional undercooling, and the formation of extra-potential particles are taken into account in the calculations. It is shown that the calculated results are in reasonable agreement with the experimental data.